Medium severity · published Sep 16, 2026
CVE-2026-76439
Cisco Identity Services Engine Event Injection Vulnerability
5.3
CVSS
0.4%
EPSS
No
On KEV
Description
A vulnerability in the endpoint posture status reporting functionality of the guest portal web application of Cisco ISE could allow an unauthenticated, remote attacker to submit forged posture status events into the endpoint posture pipeline. This vulnerability is due to insufficient authentication on an internal interface that is exposed through the guest portal. An attacker could exploit this vulnerability by sending a crafted request to an affected system. A successful exploit could allow the attacker to manipulate the posture status on the affected system.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CI
Cisco ISE Passive Identity Connector · Cisco
3.2.0; 3.1.0; 3.3.0; 3.4.0; 3.5.0 · source: vendor
CI
Cisco Identity Services Engine Software · Cisco
3.1.0; 3.1.0 p1; 3.1.0 p3; 3.1.0 p2; 3.2.0; 3.1.0 p4; +34 more · source: vendor
IS
Identity Services Engine · Cisco
before 3.3.0; 3.3.0; 3.3.0; 3.3.0; 3.3.0; 3.3.0; +17 more · source: NVD
IS
Identity Services Engine Passive Identity Connector · Cisco
before 3.3.0; 3.3.0; 3.3.0; 3.3.0; 3.3.0; 3.3.0; +13 more · source: NVD
Affected product
CI
Cisco Identity Services Engine Software
Cisco
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